1. Field of the Invention
The present invention relates to wheel hubs and primarily bicycle type wheel hubs with clutches where the hub is free wheeling when torque is not being applied to the hub through a gear that is linked by a chain to a peddle arrangement, and will engage to transfer torque to a hub wheel when torque is applied to the peddle assembly.
2. Prior Art
Wheel hubs having clutches capable of free wheeling when a torque is not being applied thereto, as through a chain linked to a peddle arrangement, or like driving arrangement, but will engage to transmit torque to turn a hub wheel as generated by an operator turning such peddle arrangement are, of course, well known, and are in common use. For example, on bicycles that are directly driven through a single gear, or include multi-speed gearing. One such earlier hub design, that is believed to be the basic design of most earlier hubs for use with multi-speed gearing, is shown in FIGS. 1, 2A and 2B and is described as prior art in the Detailed Description portion of this application. This earlier hub, unlike the invention, is a ratchet type design that includes an annular ring gear that has its outer circumference secured to the inner wall of a hub body and includes teeth or notches formed around the ring gear inner circumference that slope in the direction of turning of the hub body when it is free wheeling, and includes pawls that are spring biased and are connected to extend outwardly at spaced intervals from around a peddle assembly that each have a tooth end. In free wheeling operations, the outwardly biased pawl tooth ends will each travel up the slope of each ring gear tooth or annular notch, and with the spring biasing to extend each pawl tooth end to cause the pawl end to travel down the tooth or annular notch face and engage the next tooth or annular notch face. Thereby, when the peddle assembly is turned, that turning will be against the slope of the ring gear teeth or annular notch, and the pawl tooth ends will engage and bind against the ring gear teeth faces or annular notches, transmitting an applied torque through the ring gear and into the wheel hub body to drive the wheel.
The above described spring-actuated ratchet type design for a hub clutch has, since the early nineteen hundreds, been the standard for over-running wheel hub transmissions. In practice, such spring-actuated ratchet type design provides a torque transfer from a peddle assembly, or the like, to turn a wheel at the expense of reliability and durability and accordingly necessitates high-maintenance costs. This is because the hub clutch components, specifically the pawls and their springs, are exposed to high cyclical fatigue and are therefore failure prone. Such failure is characterized by cracked pawls, or broken or bent springs. Typically, in the event of a failure of only one of the springs or pawls, a typical lightweight, high performance wheel hub will suffer a rapid deterioration of the remaining spring pawl components, resulting in total hub failure.
Additionally, earlier systems as have employed ball bearing assemblies for power transfer through a hub to turn a wheel have not included a series of spaced pockets that each incorporates a sloping side configuration like that of the invention and have required that each ball bearing carry both a radial load, that is applied perpendicular to the bearing assembly, and axial loads as are transmitted through the axle. In such earlier systems, higher friction forces have resulted from a scrubbing of the bearing surface as occurs at the portion of the ball bearing that carries radial loads with the bearing portion as supports radial loads tending to rotate faster than the ball bearing portion that is carrying thrust loads. In the invention, radial loads are contained and carried at an annular race and seat portion wherein the spaced sloping pockets of the hub assembly are formed, and the hub assembly preferably includes a separate axle thrust bearing or bearings that incorporate radially spaced needle bearings to support axial loads.
Unlike earlier wheel hub designs, the hub of the invention will not deteriorate when exposed to cyclical fatigue, in that it does not include the vulnerable and unreliable spring biased pawls, but rather employs a unique combination of hub body race arrangement that is formed as spaced sloping pockets and opposing annular ring that includes spaced cup or step segments with ball bearings installed into which opposing sloping pockets and cup or step segments, providing immediate engagement upon receipt of a torque or turning force.
The invention is in a wheel hub constructed to provide low rolling resistance, greater load carrying capacity with enhanced torque transmission, that is more reliable and will therefore operate reliably at less cost. The hub is free-rolling, providing over-running in a clock-wise or forward turning direction, but provides a nearly instantaneous clutch locking when a peddle or like drive force is applied thereto, as through a chain. So arranged, nearly instantaneous torque transfer is provided through the hub, as when the hub of the invention is in use with a bicycle driven wheel. The hub of he invention facilitates torque transfer through a multitude of ball bearings that are each housed in contoured pockets that interface with an opposing face of an annular ring of the hub body whereto a wheel is supported through spokes, ribs, or the like. The clutch bearing system of the invention is to carry a radial load that is the load that results perpendicular to the hub as from a road surface, with the applied loads transferred through a coupling of the hub outer and annular sections.
For the wheel hub clutch of the invention, the hub outer section pockets slope rearwardly from a greater to lesser height in a direction that is counter to the direction of the applied torque. Thereby, when torque is applied in the direction of hub free-wheeling, ball bearings maintained in the hub pockets will each instantly travel opposite to the applied torque, and travel upwardly along the pocket slopes towards the pockets lesser height sections, traveling upwardly along the pocket slope to bind against the ring steps. In clutch operation, the hub interior and exterior sections are thereby connected at multiple points therearound, equally distributing the applied torque through as many as ten ball bearings.
For carrying axial loads that are parallel to the road surface and are transmitted through the axle, the invention can include at least one thrust bearing fitted between the hub interior and exterior sections that includes a pair of like disk shaped plates that are fitted together and have radially spaced cylindrical openings that align as pairs to each receive a needle bearing journaled therein. In the invention, applied radial and axial loads are supported by the combination of ball and needle bearings that operate in conjunction with standard roller bearings as are fitted between a stationary axle and support the hub whereto a rim is mounted, as through spokes, or like arrangement.
It is a principal object of the present invention to provide a hub clutch bearing assembly that provides for a nearly instantaneous coupling of hub inner and annular sections across ball bearings for transferring torque from the hub inner section to the outer section whereto a wheel rim is secured.
Another object of the present invention is to provide a wheel hub clutch consisting of inner and outer hub sections, with the inner section for mounting to an axle that is turned by a peddle arrangement to transfer torque thereto, and with the inner section including a ring having spaced contoured pockets formed therearound that are each fitted with a ball bearing, and with the hub outer section including an annular ring having spaced steps sections, and with each ball bearing to nest and bind between a pocket surface and a ring step, transferring torque thereacross.
Another object of the present invention is to provide the inner ring with contoured pockets that slope upwardly from a deep section in the direction of wheel turning, whereby each ball bearing, at peddle turning, will roll oppositely to the direction of peddle turning, traveling upwardly along the pocket contour and into engagement with an adjacent ring step, causing the ball bearing to bind therebetween, transferring torque from turning the peddle arrangement into the turning hub outer section.
Another object of the present invention is to provide a wheel hub that will present a minimum rolling resistance in a free-wheeling mode and includes a clutch that will nearly instantly and positively connect to transmit torque when a peddle arrangement is turned, and will quickly disengage when a peddle turning force is removed.
Another object of the present invention is to provide a wheel hub clutch where engagement of hub inner and outer sections is through a plurality of ball bearing where the ball bearings each turn between engagements and thereby preclude scuffing of the ball surface over time and repeated couplings.
Still another object of the present invention is to provide a wheel hub where hub inner and outer section coupling is through ball bearings for supporting road forces as are directed perpendicularly into the hub, with the hub further including at least one thrust bearing fitted between the hub sections for supporting side or axial loads.
Still another object of the present invention is to provide a thrust bearing that consists of needle bearings that are mounted radially in a disk shaped body that is open through its center to receive an axle fitted therethrough, with the thrust bearings to support side or axial loads as are directed into the hub.
Still another object of the present invention is to provide a wheel hub clutch that is simple and economical to manufacture and will provide a sure and nearly instantaneous engagement to transfer torque, as from a turning peddle arrangement, to turn a wheel whereto the hub is mounted